Velocity of domain-wall motion induced by electrical current in a ferromagnetic semiconductor (Ga,Mn)As

TL;DR

This study measures the velocity of domain-wall motion induced by electrical current in a ferromagnetic semiconductor, providing experimental data to test spin-transfer theories and revealing domain-wall creep at low currents.

Contribution

It offers the first comprehensive measurement of current-induced domain-wall velocities in (Ga,Mn)As and compares results with theoretical models of spin-transfer mechanisms.

Findings

Domain-wall velocity reaches up to 22 m/s

Evidence of domain-wall creep at low currents

Data supports spin-transfer torque theories

Abstract

Current-induced domain-wall motion with velocity spanning over five orders of magnitude up to 22 m/s has been observed by magneto-optical Kerr effect in (Ga,Mn)As with perpendicular magnetic anisotropy. The data are employed to verify theories of spin-transfer by the Slonczewski-like mechanism as well as by the torque resulting from spin-flip transitions in the domain-wall region. Evidence for domain-wall creep at low currents is found.